My filler plug on the transfer case is stuck solidly. After stripping it with a socket , I've tried the vice grips, the bigger vice grips, the Knipex pliers, a smaller cheap Chinesium socket hammered on and nothing. There's not really room for the bobbejaan in there.

I'm left with two choices:
Break an easy-out off in it

Weld on a nut.

I'm worried that since the transfer case body is aluminium, welding a nut to the filler plug (which seems to be steel, since it's magnetic) might damage the case body. I only have an arc/stick/SMAW welder so its going to be interesting. Any advice, cautionary tales will be gratefully accepted.

As long as you do not draw an arc on the aluminium it should be fine. Fortunately the welding will not stick to the aluminium. I once tried to help a guy who had managed to weld a broken bolt very nicely to the cast iron engine block. That was a bit of fun. I have welded out broken studs/nuts from aluminium cylinder heads and engine casings without issue before using an arc welder. The process of welding a nut onto the plug has the added benefit of really making the plug very hot which causes it to expand. Once cooled off you might actually find that the plug comes out much easier.

Make sure that you disconnect the alternator (all the wires) before you start welding (and maybe even the earth clamp of the battery for good measure).

As long as you do not draw an arc on the aluminium it should be fine. Fortunately the welding will not stick to the aluminium. I once tried to help a guy who had managed to weld a broken bolt very nicely to the cast iron engine block. That was a bit of fun. I have welded out broken studs/nuts from aluminium cylinder heads and engine casings without issue before using an arc welder. The process of welding a nut onto the plug has the added benefit of really making the plug very hot which causes it to expand. Once cooled off you might actually find that the plug comes out much easier.

Make sure that you disconnect the alternator (all the wires) before you start welding (and maybe even the earth clamp of the battery for good measure).

+1

If you're going to weld under there, button your collar right up (not funny if splatter or slag gets into your shirt ... ask me ... ) and use long welding gloves if you have.

When your road comes to an end ...... you need a HILUX!.

Life is like a jar of Jalapeño peppers ... what you do today, might burn your ass tomorrow.Don't take life too seriously ..... no-one gets out alive.It's not about waiting for storms to pass. It's about learning to dance in the rain.And be yourself ..... everyone else is taken!

The cold chisel story works, especially on bigger diameter bolts and nuts but personally I would avoid too much hammering around the aluminium casing for fear of cracking it. I would still go the welding route, but carefully. Find a big nut that fits over the damaged plug end and weld it on the inside of the nut.

When your road comes to an end ...... you need a HILUX!.

Life is like a jar of Jalapeño peppers ... what you do today, might burn your ass tomorrow.Don't take life too seriously ..... no-one gets out alive.It's not about waiting for storms to pass. It's about learning to dance in the rain.And be yourself ..... everyone else is taken!

Life is like a jar of Jalapeño peppers ... what you do today, might burn your ass tomorrow.Don't take life too seriously ..... no-one gets out alive.It's not about waiting for storms to pass. It's about learning to dance in the rain.And be yourself ..... everyone else is taken!